1. Field of the Invention
The present invention relates to an input device, and more specifically, to an input device utilizing a sliding member of a second keyboard to slide relative to a first keyboard and a guide rail of a casing for performing an expanding operation or a folding operation.
2. Description of the Prior Art
In recent years, a portable electronic device (e.g. a PDA (Personal Digital Assistant) or a mobile phone) has been widely used in daily life. For improving its portability, omission of a keyboard or reducing a volume of a keyboard (e.g. reducing number of keyswitches on the keyboard) is usually applied to the portable electronic device. However, the said designs usually cause a user much inconvenience in performing paperwork operations. Thus, a foldable keyboard has been developed accordingly.
A conventional foldable design is to utilize hinges to be pivotally connected between foldable sections of a keyboard for making the keyboard foldable. However, the said design may cause a complicated structure and influence the outer appearance and the input operations of the keyboard due to disposal of the hinges.